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Current Problems on 9mm diode and 2.4A driver

bobo99

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May 18, 2011
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Hey Guys,

I bought 2x9mm 445 packages from DTR with a 2.4A x-drive driver. I didn't verify the output of either driver.

Now I built the laser, and heatsinked the driver very well.

Turn on the laser and LPM it, only 1.9W.

So I measure the current at the cap, and only get 1.8A:thinking:

So last resort different batteries, and this is where it got strange.
Using these fully charged batteries :
Panasonic Super Max 3.7V 3400mAh Rechargeable Li-ion Battery - Black + Green (2 Pieces)
I got 1.8A

Genuine SANYO 18650 3.7V 2600mAh Rechargeable Battery - Red (Pair) - Free Shipping - DealExtreme gives me 1.9A

and my generic trustfire give me 2.0A.

To note, I bought 2x9mm packages and have built two hosts in parallel, both exhibit the same problem. The hosts are the same.

The only thing I can think of is the custom host's "screw" making contact between the battery and the circuit, has too high a resistance. Before I take it apart I'd like to get some input from you guys.
 





sinner

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Looks like it could be anything, taking apart is probably a better idea just do some double checks step by step, as if you are rebuilding from scratch.. Some pics would also help us if you donot want to open it up. We do need to know how drivers are mounted and the leads are connected properly.

The resistance can be the issue, You may need to send it to a local member/builder/vet like ARG he's pretty good, I believe these are not batteries that are the issue, Some photos of your setup would give a slightly better idea where to start looking..
 

djQUAN

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x-drive? I think it's a buck driver meaning it steps the voltage down from two cells to what the diode needs and reducing the amps drawn from the batteries in the process.
 

Blord

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^^^ like he said. Did you use two 3.7V li-ion cells for the lasers ? These buck drivers needs two cell instead of one cell.
 
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May 12, 2013
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When you say you measured the current at the cap does this mean that you measured the current draw from the tailcap? If so then your readings for the tailcap current draw may be correct, since buck drivers tend to draw less current than they are actually supplying to the diode.

As said above make sure you're using two li-ion cells since buck drivers require the total voltage from two 3.7 volt batteries to run properly.
 
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It IS weird though that you're only getting 1.9W out. Don't think I have ever seen a 9mm that is that inefficient.
 

DTR

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Do you mean 2.3A drivers? I don't have a 2.4A option.

Also what lens are you using? If you are using a three element lens you are probably right on it.;)

If it is drawing 1.8A and you are using two Li-ions the current is probably correct at 2.3A to the diode since buck drivers turn extra voltage into current and that is about what they draw with two fully charged Li-ions @ 2.3A to the diode.
 
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bobo99

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My mistake... it is a 2.3A driver.

I am running it on two of the previously mentioned cells.

When measuring at the cap, I remove the cap, and complete the circuit by putting my ammeter in series with battery to body of host.

The driver/laser/batteries seem to have a warmup period. Current draw as mentioned above starts at 2.0A and in about 30 seconds goes up to 2.2A.. those numbers check out then. My LPM only goes up to 2W so perhaps it was reading wrong at the higher range.

I took the head out and ruled out the switch, so all these numbers check out! Thanks guys, false alarm!IMG_2226.JPG
 
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DTR

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What lens did you get with the units?
 
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DTR

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Ok so you extracted the stock lenses and mounted them in lens holders. Everything went well in the extraction and they came out nice and clean?
 

bobo99

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Sorry today's been a long day. I got the 117 dollar option from your site and using it as is.
 

DTR

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Oh then you never took the acrylic's out. You will need to ditch them. YOu can either get lens barrels for the stock lenses that were in the package, get some G-2's or get three element glass lenses. All I can say is you really need to ditch the acrylic's they are just there to keep the dust out.:beer:
 




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